Slitting tool

ABSTRACT

A tool for slitting an elongate sheath from about an elongate member that is disposed within a longitudinally extending lumen of the sheath includes a longitudinally extending tail portion projecting rearward of a slitting edge and a nose portion of the tool; a lower surface of the nose portion is disposed beneath the slitting edge for engaging a portion of the elongate member. The tail portion of the tool, approximately aligned with the sheath lumen when the lower surface, engages the elongate member and a leading edge of the nose portion is within the sheath lumen, is sized to fit within the sheath lumen after the sheath is slit by the slitting edge. A passageway between the nose portion and the tail portion allows a proximal segment of the elongate member to bend away from the tail portion when the elongate member is engaged by the nose portion.

This application is a continuation of U.S. patent application Ser. No.12/882,625, filed on Sep. 15, 2010 (now U.S. Pat. No. 8,074,360), whichis a continuation of U.S. patent application Ser. No. 11/343,349 filedon Jan. 31, 2006, now U.S. Pat. No. 7,950,155, both of which areincorporated herein by reference.

FIELD OF THE INVENTION

The present invention pertains to slitting tools and more particularlyto slitting tools facilitating removal of an elongate sheath or catheterfrom about an elongate member disposed therein.

BACKGROUND OF THE INVENTION

Sheaths, or catheters, are commonly used in minimally invasive medicalprocedures, for example, to provide a pathway for the introduction ofelongate medical devices into the vascular system of a patient Manymedical devices, introduced in such a manner, through a lumen of thesheath, are intended to indwell within the patient for a prolongedperiod, for example, extending from a number of days to many years.After the indwelling medical device has been inserted within the lumenof the sheath, for positioning within the patient, it is desirable toremove the sheath from the patient without dislodging the indwellingdevice.

A number of slitting tools, known to those skilled in the art, are usedto remove sheaths from about indwelling medical devices. However, thesetools present one or more difficulties to the user, for example, withrespect to handling.

BRIEF DESCRIPTION OF THE DRAWINGS

The following drawings are illustrative of particular embodiments of thepresent invention and therefore do not limit the scope of the invention.The drawings are not to scale (unless so stated) and are intended foruse in conjunction with the explanations in the following detaileddescription. Embodiments of the present invention will hereinafter bedescribed in conjunction with the appended drawings, wherein likenumerals denote like elements.

FIGS. 1A-B are an end view and a side plan view, respectively, of aslitting tool according to one embodiment of the present invention.

FIG. 1C is a section view through section line A-A of FIG. 1B.

FIG. 2 is a schematic plan view, including, a partial section, depictinga method for using a slitting tool according to some embodiments of thepresent invention.

FIG. 3A is a top view of the slitting tool, shown in FIGS. 1A-C, cuttingthrough a portion of a sheath wall.

FIG. 3B is a section view through section line B-B of FIG. 3A.

FIGS. 4A-B are a side plan view and an end view of a slitting toolaccording to another embodiment of the present invention.

FIG. 5A is a schematic showing an alternate embodiment of a slittingtool in a position for slitting a sheath.

FIG. 5B is an end view of FIG. 5A.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

The following detailed description is exemplary in nature and is notintended to limit the scope, applicability, or configuration of theinvention in any way. Rather, the following description providespractical illustrations for implementing exemplary embodiments of thepresent invention.

FIGS. 1A-B are an end view and a side plan view, respectively, of aslitting tool 10, according to one embodiment of the present invention;and FIG. 1C is a section view through line A-A of FIG. 1B. FIGS. 1A-Cillustrate tool 10 including a nose portion 16, a handle portion 17, aslitting edge 12 extending between nose portion 16 and handle portion17, a longitudinally extending tail portion 14, and a passageway 15disposed between nose portion 16 and tail portion 14, and extendingupward into handle portion 17. FIGS. 1A-B further illustrate noseportion 16 including a lower surface 11 and a leading edge 13. Accordingto the illustrated embodiment, slitting edge 12 is part of a metallicblade member 120 mounted in handle 17; according to alternateembodiments, slitting edge is an integral part of material forming tool10 as a whole. Tool 10 may be formed of a rigid plastic, a ceramic, ametallic material or a combination thereof.

According to the illustrated embodiment, lower surface 11 of noseportion 16 is adapted to engage an elongate member 100, and FIG. 1Cshows elongate member 100 extending from nose portion 16 into passageway15 such that a proximal segment 100′ of member 100 bends away from tailportion 14. With reference to FIGS. 1B-C, passageway 15 extends fromnose portion 16 up into handle 17, being flanked on either side by asidewall 150; passageway 15 further extends into, grooves 15′, which areformed along opposing outer surfaces 17′ of handle 17 and either ofwhich can-accommodate segment 100′. An operator, gripping handle 17 oftool 10, may hold proximal segment 100′ of elongate member 100 in one ofchannel grooves 15′, as illustrated in FIG. 2.

FIG. 2 is a schematic plan view, including a partial section, depictinga method for using slitting tool 10 according to some embodiments of thepresent invention. FIG. 2 illustrates elongate member 100, for example,an implantable medical electrical lead, disposed within a lumen 25 of asheath 200; sheath 200 is shown including a tubular sheath wall 20terminated at a proximal end by a hub 22. FIG. 2 further illustrates afirst thumb 25 and forefinger 26 of an operator holding slitting tool 10and proximal segment 100′ of member 100, while a second thumb 205 andforefinger 206 hold a hub handle 220 to pull sheath 200, per arrow A,against slitting edge 12 of tool 10. Nose portion 16 of tool 10 is shownengaging elongate member 100 while proximal segment 100′ bends throughpassageway 15 that extends along an operator grip zone 19, which, onopposing surfaces 17′ of handle 17, is generally located in the zoneindicated by cross-hatching. According to the illustrated embodiment,tail portion 14 of tool 10 is approximately aligned with sheath lumen 25and is sized to fit within sheath lumen 25, when slit, so that tailportion 14 will ride within sheath lumen 25 after slitting edge 12 cutsthrough hub and sheath wall 20. According to some embodiments, tailportion 14 further includes a profile closely conforming with slitsheath lumen 25, for example as illustrated in FIG. 3B.

FIG. 3A is a top view of the slitting tool, shown in FIGS. 1A-C, cuttingthrough a portion of sheath wall 20; and FIG. 3B is a section viewthrough section line B-B of FIG. 3A. FIGS. 3A-B illustrate sheath 200having been pulled, per arrow A, so that sheath wall 20 has been slit bytool slitting edge 12 (FIGS. 1A-B and 2) and tool tail portion 14 isdisposed within lumen 25, downstream of slitting edge 12; slit edges 32of sheath wall 20 emanate from slitting edge 12 beneath tool handle 17,shown by dashed lines, and extend downstream of tool 10; fingers 25, 26and associated hand of the operator holding tool 10 (FIG. 2) are notshown so that the view of tool 10 and slit edges 32 of sheath wall 20 isnot obstructed. FIG. 3B further illustrates a profile of tail portion14, formed by a continuous exterior surface extending thereabout, whichclosely mates with slit sheath lumen 25; a width P of tail portion 14may be approximately equal to or slightly greater than a pre-slitdiameter of sheath lumen 25, or may be up to two times greater than thepre-slit diameter of lumen 25. FIG. 3B further illustrates tool 10including a shank 18 joining handle 17 to tail portion 14; according tosome embodiments, a thickness T of shank 18 is greater thanapproximately 0.01 inch and less than width P of tail portion 14.

According to embodiments of the present invention, tail portion 14 mayserve to stabilize tool 10 as it cuts through sheath wall 20 and mayfurther prevent slit edges 32 from collapsing toward one another in away which may cause slit sheath lumen 25 to ‘grab’ elongate member 100,as sheath 200 is pulled, per arrow A, thereby dislodging a distal end ofmember 100. An effective length of tail portion 14, for stabilizing tool10 as it cuts through sheath wall 20, may be approximately equal to orgreater than ½ inch. Although, in FIG. 2, tail portion 14 is illustratedextending proximally from operator grip zone 19 of handle portion 17,embodiments of the present invention are not so limited.

FIGS. 4A-B are a side plan view and an end view of a slitting tool 40according to another embodiment of the present invention. FIGS. 4A-Billustrate tool 40 including a nose portion 46, a handle portion 47, aslitting edge 42 extending between nose portion 46 and handle portion47, and a longitudinally extending tail portion 44. FIGS. 4A-B furtherillustrate nose portion 46 including a lower surface 41 extending from aleading edge 43 to a passageway 45 that extends from between noseportion 46 and tail portion 44, upward into handle portion 47. Accordingto the illustrated embodiment, to facilitate loading of elongate member100 into passageway 45, for example, as shown in FIG. 4A, tail portion44 is split into a first leg 404A and a second leg 404B. FIG. 4B showseach leg 404A, B including a foot 44A and 44B, respectively; feet 44A, Btogether form a tail profile, to mate with a slit lumen of a sheath orcatheter, when legs are forced, per arrows B, together, as shown withdashed lines; the resulting profile is similar to that of solid tail 14illustrated in FIG. 3B. Legs 404A, B would be forced together in such away when a sheath is pulled past slitting edge 42 of tool 40 such thattail 44 is enclosed by the slit lumen of the sheath.

FIG. 5A is a schematic showing an alternate embodiment of a slittingtool 50 in a position for slitting sheath 200; and FIG. 5B is an endview of FIG. 5A. FIG. 5A illustrates tool 50 including a nose portion56, a handle portion 57, a slitting edge 52, extending between noseportion 56 and handle portion 57, and a longitudinally extending tailportion 54, which is joined to handle portion 57 by a shank 58. FIG. 5Afurther illustrates nose portion 56 engaging elongate member 100 and apassageway 55, disposed between nose portion 56 and tail portion 54,allowing proximal segment 100′ of elongate member 100 to bend away fromtail portion 54. According to the illustrated embodiment, fingers 25 and26, associated with the hand of the operator, hold segment 100′ againstan operator grip zone 59 of handle 57, the extent of which generallycorresponds to the cross-hatched area shown in FIG. 5B.

In the foregoing detailed description, the invention has been describedwith reference to specific embodiments. However, it may be appreciatedthat various modifications and changes can be made without departingfrom the scope of the invention as set forth in the appended claims.

The invention claimed is:
 1. A tool for slitting an elongate sheath fromabout an elongate member disposed within a lumen of the sheath, the toolcomprising: a slitting edge directed forward to slit an elongate sheath;a handle portion carrying the slitting edge, wherein the handle portioncomprises opposing outer surfaces, wherein at least one of the opposingouter surfaces has a groove defined therein to receive at least aportion of an elongate member when an elongate sheath is being slit; anda nose portion extending from a leading edge proximate the slitting edgeto a rear portion thereof, wherein the nose portion comprises: a lowersurface open downward to contact a portion of an elongate member when anelongate sheath is being slit, wherein the lower surface proximate theleading edge defines a linear passageway along an axis in which anelongate member is located when an elongate sheath is being slit, andfurther wherein the rear portion of the nose portion defines anon-linear passageway deviating from the axis and extending to thegroove defined in the at least one opposing outer surface of the handleportion to allow a portion of an elongate member to bend upward and awayfrom the axis when an elongate sheath is being slit; and one or moreseparation surfaces extending along at least a portion of the linearpassageway and at least to a location rearward of the deviation of thenon-linear passageway from the axis of the linear passageway to separatea portion of an elongate member received within the non-linearpassageway proximate the linear passageway from the slit edges of anelongate sheath when an elongate sheath is being slit.
 2. The tool ofclaim 1, wherein the one or more separation surfaces comprise one ormore outwardly facing surfaces flanking the linear passageway extendingalong the axis and at least a portion of the non-linear passagewayextending upward into the handle portion, the one or more outwardlyfacing surfaces comprising one or more sheath contact surfaces extendinglinearly along the axis opposite the lower surface and at least to alocation rearward of the deviation of the non-linear passageway from theaxis of the linear passageway, wherein the one or more sheath contactsurfaces separate the portion of an elongate member received within thenon-linear passageway proximate the linear passageway bending upward andaway from the axis and the slit edges of an elongate sheath when anelongate sheath is being slit.
 3. The tool of claim 2, wherein the oneor more outwardly facing surfaces flanking the linear passagewayextending along the axis and at least a portion of the non-linearpassageway extending upward into the handle portion comprise sidewallsflanking either side of the non-linear passageway extending upward intothe handle portion.
 4. The tool of claim 1, wherein at least the lowersurface proximate the leading edge of the nose portion defining thelinear passageway comprises a concave surface for receiving a portion ofan elongate member when the elongate sheath is being slit, and furtherwherein the one or more separation surfaces comprise convex surfacesflanking either side of the linear passageway and extending along theaxis to a location rearward of the deviation of the non-linearpassageway from the axis of the linear passageway.
 5. The tool of claim1, wherein each of the opposing outer surfaces have a groove definedtherein for receiving at least a portion of an elongate member when anelongate sheath is being slit, the groove on each opposing outer surfacebeing located such that the fingers of the operator holding the handleportion also hold an elongate member in the groove when an elongatesheath is being slit, and further wherein the non-linear passagewayextending upward into the handle portion extends to the groove definedin each of the opposing outer surfaces.
 6. The tool of claim 1, whereinthe slitting edge is mounted in the handle.
 7. The tool of claim 1,wherein the tool further comprises a longitudinally extending tailportion projecting rearward of the slitting edge and rear portion of thenose portion, the tail portion extending between a first end and asecond end downwardly from a portion of the handle portion and separatedfrom the rear portion by the non-linear passageway, the tail portionbeing approximately aligned with the axis of the linear passageway andsized to fit within a sheath lumen after an elongate sheath is slit bythe slitting edge such that the tail portion mates within the slitsheath lumen and prevents the slit edges of the elongate sheath fromcollapsing toward one another.
 8. A method of slitting an elongatesheath from about an elongate member disposed within a longitudinallyextending lumen of the elongate sheath, the method comprising: providinga slitting tool, wherein the slitting tool comprises: a slitting edgedirected forward to slit an elongate sheath; a handle portion carryingthe slitting edge, wherein the handle portion comprises opposing outersurfaces, wherein at least one of the opposing outer surfaces has agroove defined therein to receive at least a portion of an elongatemember when an elongate sheath is being slit; and a nose portionextending from a leading edge proximate the slitting edge to a rearportion thereof, wherein the nose portion comprises: a lower surfaceopen downward to contact a portion of an elongate member when anelongate sheath is being slit, wherein the lower surface proximate theleading edge defines a linear passageway along an axis in which anelongate member is located when an elongate sheath is being slit, andfurther wherein the rear portion of the nose portion defines anon-linear passageway deviating from the axis and extending to thegroove defined in the at least one opposing outer surface of the handleportion to allow a portion of an elongate member to bend upward and awayfrom the axis when an elongate sheath is being slit; and one or moreseparation surfaces extending along at least a portion of the linearpassageway and at least to a location rearward of the deviation of thenon-linear passageway from the axis of the linear passageway to separatea portion of an elongate member received within the non-linearpassageway proximate the linear passageway from the slit edges of anelongate sheath when an elongate sheath is being slit; receiving aportion of an elongate member in the linear passageway and in contactwith the lower surface of the nose portion and receiving one or moreother portions of the elongate member in the non-linear passageway andin the groove defined in the at least one opposing outer surface suchthat the elongate member is bent upward and away from the axis of thelinear passageway; holding the handle portion with one or more fingersagainst at least the elongate member received in the groove; and pullingthe elongate sheath against the slitting edge to slit the elongatesheath.
 9. The method of claim 8, wherein the one or more separationsurfaces comprise one or more outwardly facing surfaces flanking thelinear passageway extending along the axis and at least a portion of thenon-linear passageway extending upward into the handle portion, the oneor more outwardly facing surfaces comprising one or more sheath contactsurfaces extending linearly along the axis opposite the lower surfaceand at least to a location rearward of the deviation of the non-linearpassageway from the axis of the linear passageway, wherein the one ormore sheath contact surfaces separate the portion of the elongate memberreceived within the non-linear passageway proximate the linearpassageway bending upward and away from the axis and the slit edges ofthe elongate sheath when the elongate sheath is being slit.
 10. Themethod of claim 9, wherein the one or more outwardly facing surfacesflanking the linear passageway extending along the axis and at least aportion of the non-linear passageway extending upward into the handleportion comprise sidewalls flanking either side of the non-linearpassageway extending upward into the handle portion.
 11. The method ofclaim 8, wherein at least the lower surface proximate the leading edgeof the nose portion defining the linear passageway comprises a concavesurface for receiving the portion of the elongate member when theelongate sheath is being slit, and further wherein the one or moreseparation surfaces comprise convex surfaces flanking either side of thelinear passageway and extending along the axis to a location rearward ofthe deviation of the non-linear passageway from the axis of the linearpassageway.
 12. The method of claim 8, wherein the tool furthercomprises a longitudinally extending tail portion projecting rearward ofthe slitting edge and rear portion of the nose portion, the tail portionextending between a first end and a second end downwardly from a portionof the handle portion and separated from the rear portion by thenon-linear passageway, the tail portion being approximately aligned withthe axis of the linear passageway and sized to fit within the sheathlumen after the elongate sheath is slit by the slitting edge such thatthe tail portion mates within the slit sheath lumen and prevents theslit edges of the elongate sheath from collapsing toward one another.13. The method of claim 8, wherein the slitting edge is mounted in thehandle.